Structure



A Jue l1, 1946. vw. T. VAN ORM-AN S TRUC TUBE Filed oct'. e, 1943 Ward77 Via/7 @rma/r Patented June 41v1, 1946 yPrice STRUCTURE Ward T. VanOrman, Akron, Ohio, assigner to Wingfoot Corporation, Akron, h10, acorporation of Delaware Application ctober 6, 1943, Serial No. 505,093

y is claims; (cl2-2.1i

sections with gently sloping sides, etc., which are.

adapted to be lled with a fluid under pressure. The fluid may be a gasor a liquid. uAccording to this invention, the fabric used in such cylindrical structures may be formed from squarewoven fabric by racking it,or two-ply, pickless fabric may be used. Whatever the fabric, thetextile elements-i. e., threads if basket-weave and cords if two-plypickless--rneet one another in an obtuse angle, preferably oi about 10928', with the projection of the anis of the cylinder approximatelybisecting this obtuse angle.

When a cylindrical structure in which the textile elements meet oneanother at an angle of approidmately 109 28 is placed under pressure,the longitudinal tension in the fabric is balanced by the radialtension. There is, therefore, no tendency for the cylinder to grow ineither direction at the expense of the other. Also, in a fabricstructure of this type, one obtains maximum strength with the minimumweight of material.

There is an advantage in using this type oi cylindrical structure inmany fabric products. The advantages may be due chiefly to the sav' ingin material and consequent saving in weight, as in the construction oflighter-than-air craft, or they may lie in the improvement in thephysical properties inherent in such structures, as will be more fullyexplained in what follows.

scribed in connection with the construction oi' a pressure garment, suchas a suit for an aviator or diver. The garment its'loosely on thewearer, and the space between the garment and the wearer is iilled witha gas under pressure. air or oxygen is normally used, and this, isbreathed by the wearer. Fresh gas is supplied continually, and the spentgas is continually bled from the suit. The space within the suit islrept under a pressure' of two or three or four or more pounds greaterthan the pressure on the outside. A diver will maintain the suit under apressure of one or two pounds above that of the depth of water at 4whichhe is working. .An aviator who illes at very high altitudes willmaintain the pressure within the suit at a pressure several poundsgreater than that found at these high altitudes. If the suit is to beused by a diver, it, of course, must be waterproof. This is notessential in an aviators suit. However, the fabric must be gas tight forboth types of suits.

According to this invention, the cylindrical members of the suit, suchas the arms and legs and trunk, are made of woven abric or two-plypickless in which the textile elements meet at an obtuse angle. Althoughin the preferred form of` the invention the angle is substantially 7109(or more exactly, 109 28'), there are advantages in using asubstantially larger or smaller obtuse in lighter-than-air constructionthe sections of a ship near its center are generally cylindrical. Whenmade of a balanced fabric, i. e., when constructed according to thisinvention, the amount of material employed may be kept at a minimum. Thenecessary strength may be obtained with the lightest weight cloth. Thismeans an increase in the carrying power or pay load of the ship.

Many types of hose are now usually braided. A wrapped hose of two-ply orwoven fabric is, much cheaper to construct. If an unbalanced structureis used, such as that produced by using conven\ tional, square-wovenfabric on the bias, one of two things will happen when pressure iscreated within the hose by the passage of water or other fluid throughit: either the hose will increase in .diameter and decrease in length,or it will decrease in diameter and increase in length. This will dependupon whether the radial or longitudinal tension is the greater. Any suchtendency oi' the fabric to grow in one direction at the expense of theother is overcome by constructing the hose according to this invention.

The invention will be more particularly deangle. This will be explainedin lwlciat follows.

The suit' may be designed to be worn in the sitting position or to beworn in the standing posil tion, or by designing it for an intermediateposition as shown in the drawing, its shape can most conveniently bechanged to accommodate a person whether in the sitting or standingposition. The arms may be designed to hang at the side or rest in thelap or may be designed to normally assume any other desired position,preferably a position 'which approaches a mean of the positions thewearer will be required to assume while wearing the suit. The head piecemay be of fabric,

'with transparent eyes, although a transparent dome is preferably used.The dome may be fastened to the balance of the suit in any usual orsuitable manner.

The invention will be further described in connection with theaccompanying drawing, in which Fig. 1 is a side view of a suit inperspective. Fig. 2 is a front view of the suit in perspective; Fig. 3is an enlarged section on the line 3-3 of Fig. 2; Fig. 4 is an enlargedsection on the line 4-8'of Fig. 1; Fig. 5 illustrates the relation ofthe textile elements to one another and to the axis of the suit member.Fig. 6 illustrates the exing of a I member. l

question is a knee or arm. Fig. 6 illustrates the not be flexed withoutplacing a strain on the n warp on one side of the member and retractingthe warp threads on the opposite side of the For example, suppose themember in warp 5 in any such member running parallel with its axis. Thell t is perpendicularto this. in the bent :.3 member. it is obvious thaton the outer side of the bend the *1I-larp is placed underv tension, andon the under side of the bend the warp members are compressed.

If the fabric is placed on the bias, pantographic action of the warp andfill or cords gives greater iexibiity to the fabric. of course, that thebers are not too tightly Woven to preclude such movement during 'flexingThe flexibility of the garment. however, is not solely dependent on theWarp and lill or cords being placed on the bias.

The most exible structure is that in which the threads or cords areunder the least tension. If some threads or cords are taut and othersare not under tension, the flexibility is not as great as when none ofthe threads or cords are taut; i. e., when all of the threads or cordsare under equal stress. This is true in a balanced structure; e. g., ina cylinder in which the radial tension balances the longitudinaltension. The determination of the angle required between the textileelements to produce such a balanced, cylindrical structure will beexplained by reference to Fig. 8 and the following calculations:

If P is the unit pressure and D is the diameter of the cylinder, We knowthat for a cylinder:

2 Longitudinal force h: 1rD4 P Length 1rD X tan 0 new` that t is theangle which produces h and cesnnonents which exactly balance the stressin the cylinder, referring to Fig. 8 and using the above values, we seethat:

Angle e=35 1e' d This is the acute angle between the textile elementsand a plane passed through the cylinder at right angles to its axis. Theangle between the textile elements and a projection of the axis is,therefore, 54 44'. The obtuse angle between the vtextile elements istwice this or 109 28'. For

practical piu'poses, an angle of approximately 109? is satisfactory.This is illustrated in Fig. 5.

Although the greatest flexibility is obtained by using fabric with thetextile elements at an angle of 109 428' to one another, the use offabric in which they meet at any obtuse angle (either larger or smallerthan 109 28') gives a more exible suit member under pressure than can beobtained from square-woven fabric. This is because the obtuse angleallows greater elongation than square-woven fabric. For instance, in onefabric which was tested the fabric was racked to 109 28', and theelongation measured along an axis bisecting this angle was approximatelytwice that of the conventional square-woven fabric placed on the Theelongation of the racked fabric along an axis perpendicular to thatmentioned was only about one-half that of the conventional square-wovenfabric. The elongation of fabric racked to different angles varies ac-`flexible than if the member is made of squarewoven fabric.

The warp and fill of woven fabric may be originally woven at an obtuseangie. but it will generally be preferable .to produce the desiredfabric by racking square-woven fabric, such as basketweave. This may bedone as described in U. S. Patent 1,763,569.' The preferred methodl ofobtaining the desired angle between the warp and the fill is to usesquare-woven fabric and distort it on a preparation table before it iscoated. Further distortion of smaller magnitude may be done by using aspreading machine equipped with off-angle let-ofi' bars, guides or dragsso that the fabric is drawn to one side as it leaves the spreader, andthe fill will no longer lie transverse across the sheet at a angle, butat an angle of about 109 28' to the warp. The fabric distortion need notall-begaccomplished in a single passage through the spreader, but may beincreased in each successive passage through the spreader until thedesired racking is obtained.

The fabric is preferably made of high tenacity material, such as SeaIsland, Sak or Pima cotton, or a. high tenacity rayon, such as thedouble Fortisan type, or other high, strength, continuous,

filament yarn, such as nylon, etc. With such high strength materials afabric of low gauge may be employed, and this, in itself, lendsilexibility to the fabric structure.

A loosely woven, sleazy fabric lends itself to racking more readily thana tightly woven fabric.

A basket-weave fabric, such as that with 3 x 3 woven groups illustratedin Fig. '7, or one with 5 x 5 woven groups or the like, mayadvantageously be used. l I

The 'fabric is made gas impervious by treatment with rubber or anotherplastic, preferably applied in the form of a thick cement. It isdesirable not to impregnate the fabric as this will increase itsstiffness. .Strongly adherent coatings of methylene diphenyldiisocyanate to ten parts of the rubber or other plastic, may bedesirable to obtain the adhesion required.

A cylinder formed of the racked fabric, when inflated, may show a markedtendency to twist due to the difference in the elongation of the Warpand ll or to certain stresses set up in the fabric. To nullify suchdistortion, the various cylindrical members of the suit or otherstructure are preferably made up by reversing circumferentially adjacentpieces of fabric. For example, as shown in Fig. 2, the lower leg portionI0 is made as a different unit from the boot '6 clearly. The twoparts ofthe zipper 20 are united to fabric tapes 50, which are sewn by thestitches 5I to the reinforcing strips 52, which are cemented to thepieces 23 and 24 of coated fabric. .A cushion ,63, which may berubberized fabric, is provided to insure an airtight seal between theflap 22 and the section .23 of the coated fabric to which one section ofthe zipper is attached.v The .member 54 is a stiifening member. such asa metal strip, which prevents the suit Yfrom buckling when the wearerbends forward. It in- II to which it is later attached. Also, the thighI2 is made as a separate member. These are united by the knee I3. Eachof these members I0, I2, and I3 is made of racked fabric with the warpand fill forming an obtuse angle, which in each member is approximatelybisected by a projection of the axis of that member on it. The membersI0, I2, and I3 are each made up of two sections--a front and back. Thisis illustrated by Fig. 3, which shows an enlarged section of the lowerleg member. The front and back portions of the leg member are indicatedby the numerals I4 and I5, respectively. In assembling these members,the two halves of the pattern are reversed; that is, the coating A onthe outside of the front half of the leg member is placed on the insideof the back half of this member. The side coated B, which is the innerside of the front member I4, then becomes the outside of the back memberI5. By reversing adjoining pieces which make up the members I0, i2, andi3, the tendency of any one piece to distort the member is practicallynulliiied by the opposite tendency of the adjoining piece. Similarly,each arm member is made up of two pieces which are likewise reversed.

The upper and lower trunk members are each advantageously made of foursections, as illustrated. Each is made from racked fabric with theobtuse angle of each member substantially symmetrical with respect tothe projection of its axis. Fig. 4 shows an enlarged section through thelower trunk member. The front of the garment is shown as being closedwith the `zipper 20. Any suitable closing me'ans may be employed.

Fig. t shows flaps 2i and 22 adjoined to different sections 23 and 26 ofthe lower trunk member overlapping behind the zipper to prevent theescape of air through the zipper when the suit is inflated. The rearsections of the trunk memoer are indicated by the numerals f5 and 25. Asindicated by the letters A and B', which refer to opposite sides of theuncut fabric, the alternate, adjoining pieces which make up the lowertrunk member are reversed. 2t is reversed with respectto both 20 and 25.25 is reversed with respect to both 26 and 25. 25 is reversed withrespect to both 25 and 23, and 23 is reversed with respect to both 20and 2d. This gives a -balanced structure which shows minimum distortionon inflation.

lf two-ply, pickless cord fabric is used, the plies coated with uncuredrubber or other curn able, plastic are placed on one another so that theangle between them is the desired obtuse angie. As shown in Fig. 10, thecords it in one ply make an angle of 109 28' with the cords dit in theother ply. The rubber coating is cured with the plies in this relation.

Fig. 9 gives details of the zipper-closing device shown in Fig. 4, withthe diiferent parts spaced from one another to show the constructionmost sures an airtight seal between the two flaps 2land 22.

Fig. 4 shows in section the front and back of reinforcing straps 28 and23 which pass over the shoulders and under the crotch of the suit.

' Attachments for supplying air and for bleeding the waste air may beprovided in any desired manner. These are illustrated by the feed hose35 and the spring-balanced pressure-relief valve 31. i

The helmet 40 is of transparent plastic, such as Plexiglas, although anysuitable helmet may be used, and it may be fastened to the balance ofthe suit in any desired manner. The gloves may be made as desired.Various attachments, such as heating pads, etc., may be supplied asdesired.

This application is in part a continuatlonof vmy application Serial No.458,515, filed September 16, 1942.

What I claim is: l l. A generally cylindrical structure of woven fabricwhich is adapted to be inflated and in which the warp and fill form anangle of substantially 109 which is substantially bisected by aprojection of the axis of the structure thereon.

2. A generally cylindrical structure of two-ply, pickless cord fabricwhich is adapted to be inflated, in which the cords of one ply form anangle of substantially 109 with the cords of the other ply, the anglebetween the cords being substantially bisected by a projection of theaxis of the structure thereon.

3. A generally cylindrical structure of woven fabric which is adapted tobe inflated and in which the warp and ll form an angle of substantially109 which is substantially bisected by a projection of the axis of thestructure thereon, circumferentially adjacent pieces of the fabric beingreversed.

s. A generally cylindrical fabric structure which is adapted to beinflated and in which the textile elements, such as cords, threads andthe like, form. an angle of substantially 109 to one another, whichangle is substantially bisected by a projection of the axis of thecylinder thereon, circumferentially adjacent pieces of the fabric beingreversed.

5. A generally cylindrical structure of racked, Woven fabric which isadapted to be inflated and in which the warp and lill form an angle ofsub- 13 7. A pressure garment with a generally cylinsections of thefabric being reversed with re.

spect to the section on each side oi it.

8. A pressure garment formed with a member which is generallycylindrical in shape and made of Woven fabric in which the warp and fillform an obtuse angle, which member is so placed in the garment that aprojection of the axis of the member substantially bisects the obtuseangle.

9. A pressure garment formed with a .member which is generallycylindrical in shape and made of a plurality of pieces of racked wovenfabric in which the warp and the fill form an obtuse angle, in whichmember circumferentially adjacent pieces of fabric are reversed, whichmember is so placed in the garment that a projection of the axis of themember at least approximately bisects the obtuse angle.

l0. A pressure garment formed with a. member which is generallycylindrical ln shape and made of a plurality of pieces of two-ply,pickless cord fabric with the cords in one ply at an obtuse angle to thecords in the other ply, in which member circumferentially adjacentpieces of fabric are reversed, which member is so placed in the garmentthat a projection of the axis of the member atleast approximatelybisects the ob angle.

ll. A pressure garment comprising a generally cylindrical memberfabricated from racked fabric in which the textile elements such ascords.

threads and the like forming the fabric are disv prising the memberbeing reversed to balance.

said member upon inflation thereof. l

l2. A pressure garment certain parts of which are fabricated ingenerallytubular form vIroxn at least two superposed coextensive pliesof pickless cord fabric, the cords in one4 ply being disposed in angularrelation to the corresponding cords of the other plies for producing asubstantial bal? ance between radial and longitudinal tension introducedto the part by the inflation thereof.

13. An inflatable generally tubular body formed of at least one ply ofcord fabric inwhich one set of generally parallel cords is disposed inangular relation to another set of generally parallel cords forproducing a substantial balance between radial and longitudinal tensionintroduced to the body by the inflation thereof, said angular relationbeing of the order of substantially 109 with the angle beingsubstantially bisected by the projection of the longitudinal axis of thebody in the plane of the fabric.

WARD T. VAN ORMAN.

